Designing a Production-Ready Order Management REST API with Node.js & TypeScript

Source: Dev.to

Small and medium businesses often don’t need a complex ERP system.
What they actually need is a reliable backend API to manage products, orders, and inventory — something easy to plug into a web or mobile frontend.

This article presents the design and implementation of an Order Management REST API built as a realistic backend foundation for e‑commerce platforms and logistics‑oriented products. The API targets common use cases such as:

• B2C e‑commerce platforms
• Internal order management tools for SMEs
• Startup MVPs in commerce or logistics

It covers the full lifecycle of an order, from creation to delivery, while keeping the system lightweight and easy to extend. The goal was simple: build a backend that could realistically run in production, not just a demo project.

Core Features

Authentication and Roles

• User registration and login
• JWT authentication stored in HTTP‑only cookies
• Session rotation and logout
• Password update

Roles

• CLIENT – can place orders and view their own purchases
• ADMIN – manages products, stock, and all orders

Product and Stock Management

• Full CRUD system for products
  • Public access for product listing and details
  • Admin‑only access for creation, update, and deletion
• Each product includes name, description, price, and stock quantity

Order Management

• Orders can contain multiple products
• Automatic subtotal calculation per item
• Total order amount calculation
• Stock verification before validation
• Product snapshot (name and price) at the time of order creation
• Customers can view their own orders; administrators can access all orders

Order Lifecycle

Only administrators can update the order status, making the system suitable for logistics and fulfillment workflows.

Technical Stack

• Node.js – runtime
• Express.js – minimal HTTP framework
• TypeScript – type safety and maintainability
• PostgreSQL – relational database
• Prisma – data access layer
• Zod – input validation
• Swagger / OpenAPI 3 – API documentation

This stack favors clarity, safety, and long‑term maintainability.

Architecture and Design Choices

The project uses a monolithic REST architecture, structured by domain:

• authentication
• users
• products
• orders

Each domain is separated into:

• routes
• controllers
• services
• validations
• data access layers

The structure scales well for small teams and freelancers while remaining easy to refactor into microservices later if needed.

Data Modeling and Business Logic

• A user can have multiple orders
• An order contains multiple order items
• Each order item references a product

A key design decision was to store a snapshot of product data at order time, ensuring historical accuracy even if prices change later—a detail that prevents major business inconsistencies.

Security Considerations

• JWT stored in HTTP‑only cookies to prevent token leakage
• Role‑based authorization enforced on the backend
• Strict request validation with Zod
• No unnecessary exposure of sensitive data

These choices help avoid common pitfalls in early‑stage products.

API Documentation with Swagger

The API is fully documented using OpenAPI 3:

• Endpoints grouped by domain
• Clear request and response schemas
• Documented error responses
• Examples for complex operations such as order creation

Good documentation reduces friction between backend, frontend, and external consumers — turning an API into a usable product.

Maturity Level and Next Steps

The API currently stands at an advanced MVP level:

• Feature‑complete for a simple e‑commerce platform
• Secure by default
• Clean data model
• Usable documentation

Planned improvements

• Pagination and filtering
• Logging and monitoring
• Automated testing
• Payment integration
• Advanced stock management (reservations, rollbacks)